Effects of soil surface sealing on the growth of subterranean clover (Trifolium subterraneum L.) in pot culture.

Abstract

Root growth of Trifolium subterraneum L. (var. Bacchus Marsh) in pot culture was substantially reduced when the available soil-surface pore space was reduced to 0.06 c.c. per c.c. Top growth was also reduced. Measurements of oxygen concentration in the soil atmosphere showed that both sealing of the soil surface and sowing at high density depressed oxygen concentrations in the soil. It is suggested that the available pore space at the soil surface limited gas exchange, resulting in a depression of both the quantity of respiring root tissue and the resultant oxygen concentrations. The amount of root material present at any time is a function of sowing density and may further modify the response to sealing of the soil surface.